curl_formadd() is unavailable

[sector-f]

I'm currently trying to write a file upload program. This requires sending data to a form (analogous to curl -F from the command line). I've been told that the equivalent function in native libcurl is curl_formadd(), but this function is commented out in the curl_sys crate. And, of course, this means there's no corresponding function in the curl crate.

[alexcrichton]

Ah yes, right! I had some difficulty initially with some CI and decided to not bind them in the first pass, I'll take a look now at binding them and see how it goes.

[alexcrichton]

Ok, lemme know if that works for you!

[sector-f]

Well, it looks good...but I honestly don't know enough about curl (yet) to tell if it works.

What's the correct way to take a PathBuf and then upload the corresponding file to a form?

[alexcrichton]

I believe that would look like this

[sector-f]

Seems like a step in the right direction, but I can't get it to work—though I'm willing to bet it's my fault. Here's my function:

fn upload_files(url: String, files: Vec<PathBuf>, _concurrent_uploads: u32) {
    curl::init();
    let mut handle = Easy::new();
    for file in &files {
        let mut form = Form::new();
        form.part("file").file(&file).add().unwrap();

        handle.url(&url).unwrap();
        handle.httppost(form).unwrap();

        handle.write_function(|a| {
            Ok(stdout().write(a).unwrap())
        }).unwrap();

        handle.perform().unwrap();
    }
}

However, handle.perform() is returning an Err, [26] Failed to open/read local data from file/application

[alexcrichton]

Hm and you're sure all those files exist? You may be able to use strace as well to figure out which syscall curl is issuing that's failing

[sector-f]

Hm, it apparently works with an absolute path but not with a relative one.

[alexcrichton]

Hm that's odd, the test I have is using a relative path...

[sector-f]

Actually, correction: ./foo.jpg works but foo.jpg does not.

[alexcrichton]

Oh weird, do you have an example that doesn't work in terms of a concrete setup?

[sector-f]

Oh, dear. It just got weirder.

./target/debug/curl_main room.jpg (what I'd been trying) fails. So I just copied another picture to the directory.

./target/debug/curl_main ocean.jpg succeeds.

[sector-f]

Just for posterity: the above problem was caused by a lack of null terminators.

This was fixed in 5f9fe7b